Making daylight saving permanent could save more than 30,000 deer every year, study suggests

A new study suggests that making daylight saving permanent would reduce the number of deer-vehicle collisions, potentially saving  thousands of deer and dozens of human lives. 

The study, published Wednesday in the peer-reviewed journal Current Biology estimated that up to 36,550 deer deaths, 33 human deaths and 2,054 human injuries could be prevented annually by halting the switch from daylight saving to standard time in the autumn. Permanent daylight saving time would allow for more light during peak traffic hours. 

“We were surprised at the magnitude of the results,” said Laura Prugh, an associate wildlife science professor at University of Washington who helped author the study.

Researchers previously thought deer collision numbers might “balance out” more evenly with a later sunrise and an earlier sunset, Prugh told USA TODAY.

When does daylight saving time end 2022? What it means for your clocks, calendar and sleep

Researchers analyzed more than 1 million deer collisions and 96 million hourly traffic observations and found that deer collisions are 14 times more frequent in the two hours after sunset than before sunset, according to the study. When peak traffic volumes shift to after sunset following the transition from daylight saving to standard time, there is a 16% spike in collisions the week following, the study says. 

Delaying the sunset could also save the country $1.19 billion in collision costs, according to the study. 

Wednesday’s findings come as the nation prepares to wind its clocks back by one hour early Sunday morning to shift to standard time, and amid a debate in federal government about whether to make daylight savings permanent. 

The U.S. Senate passed the Sunshine Protection Act of 2021 earlier this year, awaiting consideration by the House of Representatives. The law would make daylight saving time permanent in all but two states, Arizona and Hawaii, where they run on standard time year round. 

What is the future of DST? Year-round change depends on federal vote.

Though popular, such a switch is criticized by some who argue that later winter sunrises, as late as 9:30 a.m. in some places, one expert told USA TODAY in March, would have a negative impact on humans. Prugh hopes the study will add a new dimension to the debate in Congress.